Solar module

Abstract

The invention relates to a solar module comprising - four cell string blocks (8a, 8b, 8c, 8d) which each have one or a plurality of adjacently arranged strings (1), which each have a plurality of solar cells connected in series, wherein the four cell string blocks (8a, 8b, 8c, 8d) are arranged in a matrix of two rows and two columns, - a current guide for carrying current from the four cell string blocks (8a, 8b, 8c, 8d) which has a circular arrangement so that the four cell string blocks (8a, 8b, 8c, 8d) are connected in series, - a connection socket (6) which is situated in a region of the solar module such that it contacts all four cell string blocks (8a, 8b, 8c, 8d) connected in series.

Description

[0001] solar panel

[0002] Description:

[0003] The invention relates to a solar module. In particular, the invention relates to a solar module comprising a plurality of cell string blocks, each comprising one or a plurality of adjacent strings. The strings each comprise a plurality of solar cells connected in series.

[0004] Such a solar module is described in DE 10 2021 131977 A1. The solar module has a first module segment with a first sub-segment and a second sub-segment, wherein the first and the second sub-segment each have at least one solar cell string, and each solar cell string has a plurality of solar cells connected in series and are connected in series via a sub-segment connector. The first module segment has two bypass elements. Furthermore, the solar module has a second module segment. Between the first and the second module segment, at least one segment connector is arranged for connecting the module segments in series or parallel, which are arranged, in particular, side by side in a longitudinal arrangement perpendicular to the orientation of the solar cell strings. A junction box is arranged at one edge of the solar module. A disadvantage of the solar module is resistance losses, particularly in the sub-segment connectors.

[0005] It is an object of the present invention to provide a solar module whose individual cell string blocks can be bridged in the event of shading and can forward the generated direct current to an inverter.

[0006] According to the invention, this problem is solved by a solar module with the features of claim 1. Advantageous further developments and modifications are specified in the dependent claims. The present invention provides the possibility of a central junction box. The junction box is therefore not located at an edge or edge region of the solar module, but rather centrally or substantially centrally, so that it is located on all four cell string blocks connected in series. This is advantageous because no special edge design is required for the junction box. In addition, only a single junction box is required, not several. The junction box, also called a junction box, serves as an interface between the cell string blocks and an inverter and has the task of collecting and distributing the direct current generated by the cell string blocks.It contains appropriately designed electrical and / or electronic components. The solar module makes it possible to bridge the individual cell string blocks in case of shading and to forward the generated direct current from this and other cell string blocks connected in series to the inverter.

[0007] This type of solar module requires relatively little material and therefore incurs relatively low costs, while achieving minimal power loss. Furthermore, even when using short solar cells, the module can be produced in a practical format and exhibits an effective current-to-voltage ratio. It is also more robust against partial shading.

[0008] The invention relates to a solar module with

[0009] - four cell string blocks, each comprising one or a plurality of adjacent strings, each comprising a plurality of solar cells connected in series, wherein the four cell string blocks are arranged in a matrix of two rows and two columns,

[0010] - a current conductor for conducting current from the four cell string blocks, which is routed in a circle so that the four cell string blocks are connected in series,

[0011] A junction box is positioned in a section of the solar module so that it contacts all four of the cell string blocks connected in series. The solar module therefore has a first cell string block, a second cell string block, a third cell string block, and a fourth cell string block. The first and second cell string blocks are arranged side-by-side (i.e., in a row), the third and fourth cell string blocks are arranged side-by-side (i.e., in a row), while the first and fourth cell string blocks are arranged one below the other (i.e., in a column), and the second and third cell string blocks are arranged one below the other (i.e., in a column), all when viewed from a top view of the front of the solar module. This connects the four cell string blocks in series.Optionally, the solar module can have one or more additional cell string blocks connected in series with the four cell string blocks.

[0012] The junction box, located within a region of the solar module such that it covers all four series-connected cell string blocks, is positioned in a central area of ​​the module. This central area extends around a central point, allowing the junction box to cover approximately 0.1% to 1.0% of the module's total surface area and to be positioned at least 20 cm from the module's edge. The junction box has standard dimensions designed to accommodate the electrical and / or electronic components for four cell string blocks. This leaves the edge of the solar module free of the junction box, resulting in a design that is not specifically tailored to the edge. Instead, the junction box covers the central point, i.e., the midpoint, of a surface formed by the four cell string blocks, such as the back side of the solar module.

[0013] In a preferred embodiment, the current conductor features string connectors, each arranged along a path extending across the plurality of adjacent, parallel-connected strings of one of the four cell string blocks. The string connectors connect all strings of one of the cell string blocks. The string connectors are arranged such that they are in electrically conductive contact with the strings they connect. Preferably, the string connectors are arranged such that, during unshaded operation of the solar module, the current flows only twice across the entire length of all parallel-arranged strings. This allows for a reduction in material usage, increased module power output due to reduced series resistance, a more compact junction box design, and a reduction in solder joints.

[0014] In a preferred embodiment, the current path features additional string connectors instead of one or more string connectors, each arranged only along a fraction of the path. That is, the additional string connectors do not connect all, but only one or more, but not all, strings of a cell string block. The additional cell string connectors of a cell string block are preferably connected to each other by solder joints. This means that during operation of the solar module, the current flows not only through the string connectors and thus through the multitude of adjacent strings, but also only through the additional string connectors and thus only through a portion of the multitude of adjacent strings. The string connectors and the additional string connectors each have an individual conductor length. This design minimizes resistance losses.

[0015] Preferably, one or more of the string connectors arranged along a path between parallel-connected strings of one of the four cell string blocks are configured to carry no current during unshaded operation of the solar module. This limits the number of string connectors that carry current during unshaded operation. The at least one string connector configured to carry no current during unshaded operation of the solar module is, for example, realized by having a relatively small cross-section. In a preferred embodiment, the at least one string connector configured to carry no current during unshaded operation of the solar module has a smaller cross-section than the string connectors configured to carry current during unshaded operation of the solar module.Since the at least one string connector, which is designed to carry no current in unshaded operation, contributes no series resistance, the material used can be reduced by using a smaller cross-section for this connector. The string connectors and the other string connectors are made of copper, for example.

[0016] Preferably, the at least one string connector, which is configured to carry no current in unshaded operation of the solar module, connects two of the four cell string blocks. More preferably, the at least one string connector, which is configured to carry no current in unshaded operation of the solar module, connects the second cell string block and the third cell string block. This allows for a series connection without current flow in unshaded operation through the at least one string connector, which is configured to carry no current in unshaded operation of the solar module, of the second and third cell string blocks.

[0017] In a preferred embodiment, the current-carrying system includes leads that connect the string connectors running along an edge of the solar module to the electrical and / or electronic components of the junction box. Preferably, the leads are arranged in a plane behind the strings, i.e., in a plane between the strings and the junction box. This saves space, thereby reducing the module area and increasing the efficiency of the solar module. Preferably, the leads are arranged between the first and second cell string blocks, as well as between the third and fourth cell string blocks.

[0018] Preferably, the four cell string blocks each contain fewer than ten strings, more preferably fewer than five strings, and even more preferably between two and four strings. In a particularly preferred embodiment, the four cell string blocks each contain three strings.

[0019] In a preferred embodiment, the four cell string blocks each have three strings. The current path preferably includes further string connectors that connect two strings from two of the cell string blocks, and further string connectors that connect one string from two of the cell string blocks. Alternatively, and preferably, the current path is configured to include string connectors that connect three strings from two of the cell string blocks.

[0020] Preferably, the junction box is designed with a width at least equal to that of a string, while the length is at most half the width, where the width is a dimension extending horizontally when viewed from a front face of the solar module, and the length is another dimension extending vertically when viewed from a front face of the solar module. This makes the junction box compact.

[0021] In a preferred embodiment, the junction box has bypass lines radiating outwards in a star configuration. Preferably, a first bypass element is assigned to the first cell string block, which is electrically connected to one of the string connectors or to one of the other string connectors and to another string connector. Preferably, a second bypass element is assigned to the second cell string block, which is electrically connected to two of the string connectors. Preferably, a third bypass element is assigned to the third cell string block, which is electrically connected to two of the string connectors. Preferably, a fourth bypass element is assigned to the fourth cell string block, which is electrically connected to one of the string connectors and to one of the other string connectors and to another string connector. Thus, the junction box has bypass lines radiating outwards in a star configuration.The bypass elements are electrically connected to the respective string connector and / or further string connectors, preferably by a soldered, clamped, or welded connection. As described above, the further cell string connectors of one of the cell string blocks are electrically connected to each other, so that if one of the bypass elements is electrically connected to one of the further cell string connectors of one of the cell string blocks, it is also electrically connected to the other further cell string connector of this cell string block.

[0022] The at least one string connector, designed to carry no current during unshaded operation, is preferably arranged at least between the second and third cell string blocks. In one possible embodiment, the at least one string connector is located in a plane behind the strings, i.e., in a plane between the strings and the junction box. Since this configuration requires no surface area within the solar module, the module efficiency can be further increased. The other string connectors are preferably arranged between the first and fourth cell string blocks.

[0023] In a preferred embodiment, the junction box has four bypass elements, each assigned to one of the four cell string blocks connected in series. This gives each cell string block its own bypass element. As a result, the bypass elements do not require separate housings but are all contained within a single junction box. Preferably, the bypass elements are bypass diodes. Alternatively, the bypass elements can also be implemented as power electronics, which can, for example, enable string-wise MPP (maximum power point) tracking. Preferably, the junction box includes the solar module cables through which current is drawn from the solar module and which serve for current collection. Preferably, the solar module cables are arranged a fraction of the way between parallel-connected strings.This means that the solar module cables are not located at an edge of the solar module, but rather draw current from a relatively central area of ​​the solar module. Preferably, the junction box has bypass lines radiating out from it in a star configuration, wherein the junction box has four bypass elements, each of which is assigned to one of the four cell string blocks connected in series. The solar module has another junction box containing solar module cables that contact two of the four cell string blocks and are located only a fraction of the way between parallel-connected strings. That is, the solar module can have another junction box in addition to the first one.The junction box then has bypass elements such as bypass diodes, while the other junction box only has the solar module cables and is located a fraction of the way between the parallel-connected strings, preferably at a point where the other string connectors meet.

[0024] In a preferred embodiment, the solar module continues to have long sides and short sides, and the strings of the four cell string blocks extend parallel to the long sides.

[0025] Preferably, the solar cells have a length that is shorter than their width, preferably equal to or less than half the width, and more preferably equal to or less than a quarter of the width, wherein the width is a dimension extending horizontally when viewed from a front face of the solar cell, and the length is another dimension extending vertically when viewed from a front face of the solar cell. Particularly preferably, the solar cells are designed as quarter cells. A quarter cell represents one quarter of a full cell. That is, a quarter cell is one quarter of a full cell that has been cut into four quarters during or after manufacturing. Quarter cells are therefore solar cells that, after being manufactured as full cells, have been cut into four quarters.Cell division allows for an increase in the total area of ​​the intercellular spaces on the solar module surface compared to the total intercellular space of corresponding full cells that are not divided. This results in a higher reflection gain via the backsheet of the solar module. Therefore, with the same number of solar cells, a higher energy yield is achieved when divided into quarter cells while maintaining the same intercellular space. The step from a full cell to a quarter cell reduces the current generated in the cell by a quarter, thus lowering resistance losses. This results in a higher efficiency for the solar module.

[0026] Beyond the preferred quarter-cell configuration, it is also possible to halve, third, or fifth manufactured full cells and assemble these partial cells into solar modules. However, quarter cells are preferred. Because quarter cells have smaller dimensions than full cells, and the number of cells in a string cannot be increased indefinitely due to excessively high voltage per string, shorter strings result when using smaller cells. The present invention makes it possible to produce modules with standard dimensions and electrical current and voltage parameters despite shorter solar cell strings. Therefore, the invention is particularly suitable for quarter cells. The inventive design of the solar module allows the resistance to be kept low without significantly increasing material consumption, such as copper consumption and / or the cross-section of the string connectors.

[0027] Preferably, the solar cells – regardless of whether they are designed as full or partial cells – are configured as TopCon (Tunnel Oxide Passivated Contact) cells. Alternatively, PERC cells or multi-junction cells, such as tandem cells, can also be used. The proposed module concept is particularly preferred for the latter due to the higher voltage of the individual cells.

[0028] In a preferred embodiment, the strings comprise a number of fewer than 50, preferably fewer than 40, more preferably fewer than 30, and most preferably between 12 and 26, of individual solar cells connected in series. Preferably, adjacent strings in a row each have the same number of solar cells. More preferably, all strings have the same number of solar cells. Further features and advantages of the invention are explained in more detail in the context of the preferred embodiments described below. The following are shown schematically and not to scale:

[0029] Fig. 1 shows a sketched representation of a solar module according to a first embodiment,

[0030] Fig. 2 shows a sketched representation of a solar module according to a second embodiment; and

[0031] Fig. 3 shows a sketched representation of a solar module according to a third embodiment.

[0032] Fig. 1 shows a sketched representation of a solar module according to a first embodiment. The solar module has four cell string blocks 8a, 8b, 8c, 8d. In particular, it has a first cell string block 8a, a second cell string block 8b, a third cell string block 8c, and a fourth cell string block 8d. Each of the cell string blocks 8a, 8b, 8c, 8d has one or a plurality of adjacent strings 1. By way of example, the four cell string blocks 8a, 8b, 8c, 8d each have three strings 1. Each string 1 has a plurality of solar cells (not shown) connected in series. The solar module has long sides and short sides. The strings 1 of the four cell string blocks 8a, 8b, 8c, 8d extend parallel to the long sides. The four cell string blocks 8a, 8b, 8c, 8d are arranged in a matrix of two rows and two columns. The first cell string block 8a and the second cell string block 8b are adjacent, i.e.Arranged in a row, the third cell string block 8c and the fourth cell string block 8d are arranged side by side, i.e., in another row, while the first cell string block 8a and the fourth cell string block 8d are arranged one below the other, i.e., in a column, and the second cell string block 8b and the third cell string block 8c are arranged one below the other, i.e., in another column, as viewed from a top view of a front face of the solar module. The solar module has a current conductor for conducting current from the four cell string blocks 8a, 8b, 8c, 8d, which is routed in a loop, so that the four cell string blocks 8a, 8b, 8c, 8d are connected in series.The current conductor comprises string connectors 2, each connecting the plurality of adjacent strings 1 of the four cell string blocks 8a, 8b, 8c, 8d; further string connectors 13, each connecting a number of strings 1 less than the plurality of adjacent strings 1; and further string connectors 4, each connecting the remaining strings of the adjacent strings 1, with the further string connectors 4 and 13 being electrically connected to each other. Thus, the two further string connectors 13 connect two of the three strings 1 of the first cell string block 8a and the fourth cell string block 8d, respectively, while the two further string connectors 4 connect one of the three strings 1 of the first cell string block 8a and the fourth cell string block 8d, respectively, being electrically connected, for example, by means of a solder joint 11.

[0033] Furthermore, the current conductor includes string connectors 5, which are designed to carry no current when the solar module is operating unshaded, while the string connectors 2 carry current when operating unshaded. The string connectors 5 have, for example, a relatively small cross-section, and in particular a smaller cross-section than the string connectors 2. The string connectors 5 connect the second cell string block 8b and the third cell string block 8c. The current conductor also includes two supply lines 12, which connect the string connectors 2 to bypass elements 7 of a junction box 6.

[0034] Furthermore, the solar module has a junction box 6, which is arranged in a region of the solar module such that it is located on all four cell string blocks 8a, 8b, 8c, 8d connected in series. The junction box 6 is arranged relatively centrally, as shown in Fig. 1. The junction box 6 has four bypass elements 7, one of which is assigned to each of the four cell string blocks 8a, 8b, 8c, 8d connected in series. The bypass elements 7 are each connected to the string connectors 2, 5 and / or the further string connectors 4, 13 by means of solder joints 11. The bypass elements 7 are, for example, designed as bypass diodes. The junction box also has two solar module cables 9. The solar module cables 9 are not located at the end, but rather a fraction of the way between the parallel-connected strings 1 of the first cell string block 8a and the fourth cell string block 8d.

[0035] The first cell string block 8a is assigned a first bypass element 7, which is electrically connected to another string connector 4 and to one of the string connectors 2 via one of the supply lines 12. The second cell string block 8b is assigned a second bypass element 7, which is electrically connected to one of the string connectors 5 and to one of the string connectors 2 via one of the supply lines 12. The third cell string block 8c is assigned a third bypass element 7, which is electrically connected to one of the string connectors 5 and to one of the string connectors 2 via one of the supply lines 12. The fourth cell string block 8d is assigned a fourth bypass element 7, which is electrically connected to one of the string connectors 2 via one of the supply lines 12 and to one of the other string connectors 4. The junction box 6 therefore has bypass lines radiating out from it in a star configuration.

[0036] Fig. 2 shows a sketched representation of a solar module according to a second embodiment. The solar module shown in Fig. 2 corresponds to the solar module shown in Fig. 1, with the difference that instead of the additional string connectors, it has string connectors 3, each connecting all three strings 1 of the first cell string block 8a and the fourth cell string block 8b. The junction box 6 of the solar module shown in Fig. 2 has smaller dimensions than the junction box shown in Fig. 1. Furthermore, the solar module cables 9 are connected to one end of the string connectors 3, which is located relatively centrally when viewed from above on a front face of the solar module.

[0037] Fig. 3 shows a sketched representation of a solar module according to a third embodiment. The solar module shown in Fig. 3 corresponds to the solar module shown in Fig. 1, with the difference that it has an additional junction box 10 which has the solar module cables 9, which contact the two cell string blocks 8a, 8d and which is arranged only in a fraction of a path between parallel-connected strings 1.

[0038] Reference symbol list:

[0039] 1 solar cell string

[0040] 2 string connectors 3 string connectors

[0041] 4 more string connectors

[0042] 5 string connectors

[0043] 6 Connection box

[0044] 7 Bypass element 8 Cell string block

[0045] 9 solar panel cables

[0046] 10 additional connection boxes

[0047] 11 Solder joint

[0048] 12 supply lines, 13 additional string connectors

Claims

Patent claims:

1. Solar module with - four cell string blocks (8a, 8b, 8c, 8d) each having one or a plurality of adjacently arranged strings (1) each having a plurality of solar cells connected in series, wherein the four cell string blocks (8a, 8b, 8c, 8d) are arranged in a matrix of two rows and two columns, - a current conductor for conducting current from the four cell string blocks (8a, 8b, 8c, 8d), which is guided in a loop so that the four cell string blocks (8a, 8b, 8c, 8d) are connected in series, - a junction box (6) which is located in an area of ​​the solar module such that it touches all four cell string blocks (8a, 8b, 8c, 8d) connected in series.

2. Solar module according to claim 1, characterized in that the current flow comprises string connectors (2, 3, 5) which are each arranged along a path extending over the plurality of adjacent parallel-connected strings (1) of one of the four cell string blocks (8a, 8b, 8c, 8d).

3. Solar module according to claim 2, characterized in that the current flow has further string connectors (4, 13) instead of one or more of the string connectors (3), each of which is arranged only along a fraction of the path.

4. Solar module according to one of the preceding claims 2 or 3, characterized in that one or more of the string connectors (5) which are arranged along a path between parallel connected strings (1 ) of one of the four cell string blocks (8a, 8b, 8c, 8d) are designed to not carry any current in unshaded operation of the solar module.

5. Solar module according to claim 4, characterized in that the string connector(s) (5) which are designed to not carry current in unshaded operation of the solar module have a smaller cross-section than the string connector(s) (2) which are designed to carry current in unshaded operation of the solar module.

6. Solar module according to one of claims 4 or 5, characterized in that one or more of the string connectors (5), which are designed to carry no current in unshaded operation of the solar module, are arranged at least partially in a plane behind the strings (1 ).

7. Solar module according to one of the preceding claims, characterized in that the current conductors have supply lines (12) to connect the string connectors (2) running along an edge of the solar module to the junction box (6), wherein the supply lines (12) are preferably arranged at least partially in a plane behind the strings (1 ).

8. Solar module according to one of the preceding claims, characterized in that the four cell string blocks (8a, 8b, 8c, 8d) each have fewer than ten, fewer than five, between two and four or three strings (1 ).

9. Solar module according to claim 8, characterized in that the four cell string blocks (8a, 8b, 8c, 8d) each have three strings (1 ) and the current flow comprises the further string connectors (13) which each connect two of the strings (1 ) of two of the cell string blocks (8a, 8d), and the further string connectors (4) which each connect one string (1 ) of two of the cell string blocks (8a, 8d), or that the cell string blocks (8a, 8b, 8c, 8d) each have three strings (1 ) and the current flow comprises the string connectors (3) which each connect three strings (1 ) of two of the cell string blocks (8a, 8d).

10. Solar module according to one of the preceding claims, characterized in that the junction box (6) is designed in a width of at least that of a string (1), while the length is at most half the width, wherein the width is a dimension which extends horizontally when viewed from above on a front side of the solar module, and the length is a further dimension which extends vertically when viewed from above on a front side of the solar module.

11. Solar module according to one of the preceding claims, characterized in that the junction box (6) has bypass lines extending from it in a star configuration, that the junction box (6) has four bypass elements (7), each of which is assigned to one of the at least four cell string blocks (8a, 8b, 8c, 8d) connected in series, and / or that the junction box (6) has solar module cables (9) that are arranged only in a fraction of a path between parallel-connected strings (1 ).

12. Solar module according to claim 11, characterized in that the junction box (6) has bypass lines radiating out from it in a star configuration, that the junction box (6) has four bypass elements (7), each of which is assigned to one of the four cell string blocks (8a, 8b, 8c, 8d) connected in series, and that the solar module has a further junction box (10) which has solar module cables (9) that touch two of the four cell string blocks (8a, 8d) and which is arranged only in a fraction of a path between parallel-connected strings (1 ).

13. Solar module according to one of the preceding claims, characterized in that the junction box (6) contains bypass diodes and / or power electronics.

14. Solar module according to one of the preceding claims, characterized by long sides and short sides, wherein the strings (1 ) of the four cell string blocks (8a, 8b, 8c, 8d) extend parallel to the long sides.

15. Solar module according to one of the preceding claims, characterized in that the solar cells have a length shorter than their width, preferably being equal to or less than half the width, and further preferably being equal to or less than a quarter of the width, and particularly preferably being designed as quarter cells, wherein the width is a dimension extending horizontally when viewed from a front face of the solar cell, and the length is a further dimension extending vertically when viewed from a front face of the solar cell.

16. Solar module according to one of the preceding claims, characterized in that the strings (1 ) comprise a number of individual solar cells connected in series of less than 50, preferably less than 40, more preferably less than 30 and particularly preferably between 12 and 26.

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